{
  "bibcode": "2016GCN.20265....1B",
  "body": "D.N. Burrows (PSU), T.G.R. Roegiers (PSU), J.P. Osborne (U. Leicester),\nK.L. Page (U. Leicester), B. Mingo (U. Leicester), V. D'Elia (ASDC), A.\nD'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), L.M. McCauley (PSU) and P.\nD'Avanzo report on behalf of the Swift-XRT team:\n\nWe have analysed 9.1 ks of XRT data for GRB 161214B (D'Avanzo et al.\nGCN Circ. 20257), from 64 s to 29.6 ks after the  BAT trigger. The data\ncomprise 234 s in Windowed Timing (WT) mode (the first 9 s were taken\nwhile Swift was slewing) with the remainder in Photon Counting (PC)\nmode. The enhanced XRT position for this burst was given by Goad et al.\n(GCN Circ. 20259).\n\nThe late-time light curve (from T0+5.1 ks) can be modelled with a\npower-law decay with a decay index of alpha=0.63 (+/-0.09).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 2.54 (+0.16, -0.15). The\nbest-fitting absorption column is  1.22 (+0.33, -0.30) x 10^21 cm^-2,\nin excess of the Galactic value of 7.2 x 10^20 cm^-2 (Willingale et al.\n2013). The PC mode spectrum has a photon index of 1.94 (+0.15, -0.14)\nand a best-fitting absorption column of 9.3 (+3.9, -2.0) x 10^20 cm^-2.\nThe counts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 3.4 x 10^-11 (4.1 x 10^-11) erg cm^-2\ncount^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     9.3 (+3.9, -2.0) x 10^20 cm^-2\nGalactic foreground: 7.2 x 10^20 cm^-2\nExcess significance: <1.6 sigma\nPhoton index:\t     1.94 (+0.15, -0.14)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00726885.\n\nThis circular is an official product of the Swift-XRT team.\n\n[GCN OPS NOTE(15dec16): Per author's request, the value for alpha\nwas added in the second paragraph.]",
  "circularId": 20265,
  "createdOn": 1481778640000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 161214B: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 161214B"
}